To improve the abrasion resistance and releasability of the inner peripheral surfaces of a resin pot chamber, a gate, and the like in a manufacturing device for a magnet embedded core without using cemented carbide, the inner peripheral surface of the resin pot chamber (64), the inner peripheral surface of the gate (50), the outer peripheral surface of the plunger (62), and the like of the manufacturing device (10) for the magnet embedded core are constituted by chromium nitride layers (59, 65, 47) or the like.